Scoping systematic review of treatments for eczema

Background

Eczema is a very common chronic inflammatory skin condition.

Objectives

To update the National Institute for Health Research (NIHR) Health Technology Assessment (HTA) systematic review of treatments for atopic eczema, published in 2000, and to inform health-care professionals, commissioners and patients about key treatment developments and research gaps.

Data sources

Electronic databases including MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Skin Group Specialised Register, Latin American and Caribbean Health Sciences Literature (LILACS), Allied and Complementary Medicine Database (AMED) and Cumulative Index to Nursing and Allied Health Literature (CINAHL) were searched from the end of 2000 to 31 August 2013. Retrieved articles were used to identify further randomised controlled trials (RCTs).

Review methods

Studies were filtered according to inclusion criteria and agreed by consensus in cases of uncertainty. Abstracts were excluded and non-English-language papers were screened by international colleagues and data were extracted. Only RCTs of treatments for eczema were included, as other forms of evidence are associated with higher risks of bias. Inclusion criteria for studies included availability of data relevant to the therapeutic management of eczema; mention of randomisation; comparison of two or more treatments; and prospective data collection. Participants of all ages were included. Eczema diagnosis was determined by a clinician or according to published diagnostic criteria. The risk of bias was assessed using the Cochrane Collaboration risk-of-bias tool. We used a standardised approach to summarising the data and the assessment of risk of bias and we made a clear distinction between what the studies found and our own interpretation of study findings.

Results

Of 7198 references screened, 287 new trials were identified spanning 92 treatments. Trial reporting was generally poor (randomisation method: 2% high, 36% low, 62% unclear risk of bias; allocation concealment: 3% high, 15% low, 82% unclear risk of bias; blinding of the intervention: 15% high, 28% low, 57% unclear risk of bias). Only 22 (8%) trials were considered to be at low risk of bias for all three criteria. There was reasonable evidence of benefit for the topical medications tacrolimus, pimecrolimus and various corticosteroids (with tacrolimus superior to pimecrolimus and corticosteroids) for both treatment and flare prevention; oral ciclosporin; oral azathioprine; narrow band ultraviolet B (UVB) light; Atopiclair™ and education. There was reasonable evidence to suggest no clinically useful benefit for twice-daily compared with once-daily topical corticosteroids; corticosteroids containing antibiotics for non-infected eczema; probiotics; evening primrose and borage oil; ion-exchange water softeners; protease inhibitor SRD441 (Serentis Ltd); furfuryl palmitate in emollient; cipamfylline cream; andMycobacterium vaccaevaccine. Additional research evidence is needed for emollients, bath additives, antibacterials, specialist clothing and complementary and alternative therapies. There was no RCT evidence for topical corticosteroid dilution, impregnated bandages, soap avoidance, bathing frequency or allergy testing.

Limitations

The large scope of the review coupled with the heterogeneity of outcomes precluded formal meta-analyses. Our conclusions are still limited by a profusion of small, poorly reported studies.

Conclusions

Although the evidence base of RCTs has increased considerably since the last NIHR HTA systematic review, the field is still severely hampered by poor design and reporting problems including failure to register trials and declare primary outcomes, small sample size, short follow-up duration and poor reporting of risk of bias. Key areas for further research identified by the review include the optimum use of emollients, bathing frequency, wash products, allergy testing and antiseptic treatments. Perhaps the greatest benefit identified is the use of twice weekly anti-inflammatory treatment to maintain disease remission. More studies need to be conducted in a primary care setting where most people with eczema are seen in the UK. Future studies need to use the same core set of outcomes that capture patient symptoms, clinical signs, quality of life and the chronic nature of the disease.

Funding

The National Institute for Health Research Programme Grants for Applied Research programme.

Oral evening primrose oil and borage oil for eczema

BACKGROUND

Eczema is a chronic inflammatory skin condition, which usually develops in early childhood. Many children outgrow this disorder as they reach secondary school age, and although It may improve with age, there is no cure. Constant itch makes life uncomfortable for those with this condition, no matter what age they are, so it may have a significant effect on a person's quality of life. Its prevalence seems to be increasing as populations move from rural locations to cities. Some people, who do not see an adequate improvement or fear side-effects of conventional medical products, try complementary alternatives to conventional treatment. This is a review of evening primrose oil (EPO) and borage oil (BO) taken orally (by mouth); these have been thought to be beneficial because of their gamma-linolenic acid content.

OBJECTIVES

To assess the effects of oral evening primrose oil or borage oil for treating the symptoms of atopic eczema.

SEARCH METHODS

We searched the following databases up to August 2012: Cochrane Skin Group Specialised Register, CENTRAL in The Cochrane Library, MEDLINE (from 1946), EMBASE (from 1974), AMED (from 1985), and LILACS (from 1982). We also searched online trials registers and checked the bibliographies of included studies for further references to relevant trials. We corresponded with trial investigators and pharmaceutical companies to try to identify unpublished and ongoing trials. We performed a separate search for adverse effects of evening primrose oil and borage oil in November 2011.

SELECTION CRITERIA

All randomised controlled, parallel, or cross-over trials investigating oral intake of evening primrose oil or borage oil for eczema.

DATA COLLECTION AND ANALYSIS

Two review authors independently applied eligibility criteria, assessed risk of bias, and extracted data. We pooled dichotomous outcomes using risk ratios (RR), and continuous outcomes using the mean difference (MD). Where possible, we pooled study results using random-effects meta-analysis and tested statistical heterogeneity using both the Chi(²) test and the I(²) statistic test. We presented results using forest plots with 95% confidence intervals (CI).

MAIN RESULTS

A total of 27 studies (1596 participants) met the inclusion criteria: 19 studies assessed evening primrose oil, and 8 studies assessed borage oil. For EPO, a meta-analysis of results from 7 studies showed that EPO failed to significantly increase improvement in global eczema symptoms as reported by participants on a visual analogue scale of 0 to 100 (MD -2.22, 95% CI -10.48 to 6.04, 176 participants, 7 trials) and a visual analogue scale of 0 to 100 for medical doctors (MD -3.26, 95% CI -6.96 to 0.45, 289 participants, 8 trials) compared to the placebo group.Treatment with BO also failed to significantly improve global eczema symptoms compared to placebo treatment as reported by both participants and medical doctors, although we could not conduct a meta-analysis as studies reported results in different ways. With regard to the risk of bias, the majority of studies were of low risk of bias; we judged 67% of the included studies as having low risk of bias for random sequence generation; 44%, for allocation concealment; 59%, for blinding; and 37%, for other biases.

IMPLICATIONS FOR PRACTICE

Oral borage oil and evening primrose oil lack effect on eczema; improvement was similar to respective placebos used in trials. Oral BO and EPO are not effective treatments for eczema.In these studies, along with the placebos, EPO and BO have the same, fairly common, mild, transient adverse effects, which are mainly gastrointestinal.The short-term studies included here do not examine possible adverse effects of long-term use of EPO or BO. A case report warned that if EPO is taken for a prolonged period of time (more than one year), there is a potential risk of inflammation, thrombosis, and immunosuppression; another study found that EPO may increase bleeding for people on Coumadin® (warfarin) medication.

IMPLICATIONS FOR RESEARCH

Noting that the confidence intervals between active and placebo treatment are narrow, to exclude the possibility of any clinically useful difference, we concluded that further studies on EPO or BO for eczema would be hard to justify.This review does not provide information about long-term use of these products.

Mapping randomized controlled trials of treatments for eczema--the GREAT database (the Global Resource of EczemA Trials: a collection of key data on randomized controlled trials of treatments for eczema from 2000 to 2010)

Background

Massive duplication of effort occurs when researchers all over the world undertake extensive searches for randomized controlled trials when preparing systematic reviews, when developing evidence-based guidelines and when applying for research funding for eczema treatments. Such duplication wastes valuable resources.

Searching for randomized controlled trials of eczema is a laborious task involving scrutiny of thousands of individual references from diverse electronic databases in order to obtain a few papers of interest. Clinicians and patients who wish to find out more about a particular treatment are at risk of missing the relevant evidence if they are not trained in electronic bibliographic searching. Systematic reviews cannot be relied upon to comprehensively inform current optimal eczema treatments due to incomplete coverage and because many may be out of date.

An international, publically available and comprehensive resource which brings together all randomized controlled trials on eczema treatment using a highly sensitive search has the potential to release more filtered knowledge about patient care to those who need it most and to significantly shorten the duration and costs of many clinical eczema research and guideline projects.

Description

The Global Resource of EczemA Trials brings together information on all randomized controlled trials of eczema treatments published from the beginning of 2000 up to the end of 2010 and will be updated every month.

We searched the Cochrane Central Register of Controlled Trials in The Cochrane Library and the Cochrane Skin Group Specialised Register, MEDLINE, EMBASE, LILACS, AMED and CINHAL databases. We included 268 RCTs (24^th March 2011) covering over 70 different treatment interventions.

The structure of the Global Resource of Eczema Trials allows the user as much, or as little, specificity when retrieving information on trials as they wish, in an easy to use format. For each trial, the database gives the citation for the published report and also provides enough information to enable a user to decide whether the trial is worth further scrutiny.

Conclusions

The Global Resource of Eczema Trials has been created to facilitate knowledge mobilization into healthcare and to reduce wastage of research time through unnecessary duplication. The collective time saved by research groups around the world can now be used to make strides in optimising the treatment of eczema, in order to further benefit people with eczema. The database can be accessed free of charge at http://www.greatdatabase.org.uk